Prism-measuring device in parallel systems



April 7, 1925. 1,532,879

- 1.. w. BUGBEE PRfSM MEASURING DEVICE IN PARALLEL SYSTEMS Filed July 23, 1923 v ATTORNEYJ.

Fatented Apr. 7, 1925.

urrso STATES 1,532,879 PATENT 'FFECE.

LUCIAN W. BUG-BEE, 0E INDIANAIPOLIS, INDIANA, ASSIGNOR TO ONEPIECE BIIEOCAL LENS COIv'IPANY, OF INDIANAPOLIS, INDIANA, A CO'BPQR-ATION.

PRISM-IJIEASURIHG DEVICE IN PARALLEL SYSTEMS.

Application filed July 23, 1923. Serial No. 653,369.

1 0 all whom it may cancer 1i..-

Be it known that l, LUOIAN'VV. B'UGBEE, a citizen of the United States, and a resident of Indianapolis, county of Marion, and State of Indiana, have invented a certain new and useful Prism-lifeasuring Device in Parallel Systems; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which likenunierals refer to like parts.

This invention relates to apparatus for measuring the prismatic power of a lens at the same time asthe focal power thereof is being measured.

The chief feature of the invention consists in locating a prism measuring device in a lensometer which operates on the parallel ray system, where the parallel rays of light will pass through the prism measuring device. it may consist of an entirely new machine, or in combination with the lensometor previously made, of a prism measuring device associated therewith so that the parallel rays thereof will pass through the prism measuring device. The particular construction of lensometer or prism measuring device is immaterial excepting as hereinafter specified.

The full nature of the invention will he understood from the accompanying drawings and the following description and claims:

In the drawings, Figure 1 is a side elevation of said prism measuring apparatus. Fig. 2 the invention. Fig. 3 is a side elevation of a part of the prism measuring device herein shown. 1

This invention is not limited to any'particular form of lensometer employing the parallel system, or to any particular con struction of the prism measuring device combined therewith to form the total apparatus. That is shownherein is merely toillustrate the general nature of the invention and for that purpose well known forms of the two devices which are combined are employed and illustrated in combined apparatus, out the invention is in the combination of said devices in one apparatus for measuring the prismatic power of the lenses being measured by the lensometer, regardless of how carefully they may be ,made as to details of construction.

is a diagrammatic presentation of The lensometer 1O herein shown is of'commen form wherein there is a post 11 and a in the passage of the light from the lens 15 to the telescope, the rays 19 are parallel and the prism measuring device 20 is, there- .11 10 re, located so that said parallel rays will pass through the same. Said prism measuring device is of common and well knowir construction, carried by a bracket 21 on the frame of the apparatus, as shown, but so that the prism measuring device can be turned out of the way when not desired and he turned up int-o position when it is desired to measure the prismatic power of the lens.

In order that the eye of the observer may see the target 18 with the telescope focused for infinity, the traget must be in the principal focus of the lens 15 being tested.

-The distance between the lens 15 and the target 18 represents the focal length of the lens, said parts being relatively adjusted to each other so that said lens will focus on V the target.

The prism measuring device 20 must work in the parallel rays systemor be located so that the parallel rays between the telescope and the lens 15 will pass through the same, for otherwise the thickness of the glass in the prism measuring device will effect the accuracy of the result.

I claim, therefore, as new the introduction into a, lens focusing instrument of a prism measuringdevioe operating in a parallel ray system. In actual use, many modifications or refinements could be made which are well known to those skilled in the art and which need not be here specified. The prism measuring device should be adjustable to show not only the power of the prism,

but also the position of the base apex line.

target, means for supporting the lens to be tested, a telescope focused tor in-limty, and

' a prism measuring device in the parallel ray sc'ope, and a prism measuring device be system between the telescope and lens when supported on said lens holder, whereby both the focal and prismatic powers of a lens may be measured. e

2. Apparatus for measuring the powers of lenses, including a target, means for supporting the lens to be measured, said two meansbeing axially adjustable with relationto each other, a telescope focused for infinity and so positioned that the lens would be between the telescope and the target soparallel rays Ofllght pass "from the lens to -the telescope. and a prism measuring device between the lens and the telescope through which said parallel rays pass.

' Apparatus for measuring the powers of a lens, including an adjustable target, a telescope focused for infinity and directed-towards saidtarget, means for su pportin the lens to bemeasu'red located between the telescope and target, whereby parallelrays'o'l light will proceed from the lens to the teletween the lens and the telescope through .which said .parallel'rays of light proceed when the apparatus is in proper adjustment to register the focal power of the lens.

4. Apparatus for measuring the powers of lenses,includinga fraine,-a telescope thereon," a target axially adjustable, a lens-holder adapted 'to'hold a-lensbetween the target and telescope and adjustable towards and awayfrom the target, a; prism vim-iasuri 11g device, and means for mounting the" prisnr measuring device in said frame so that it may be" turned to-a position between the lens and telescope and "away from that position as desired.

Apparatus'for measuring the powers of lenses, including aframe, a telescope mounted thereon, a target adjustable towards and from the telescope,-a-light connected with and beyondfthe target, af-lens holder between the-target and the telescope, and a arism measurin device removabl uneunted intovand out ofitheparallelray system and adjus able for power and graduated for prism diopters, theprism cell 'rotatably adjust-able tolocate the base apex linein degrees of arc.

In witness whereof, I have hereunto affixed (my signature.

:LUCIAN W. 'BUGBEE. 

